It is well known to convert an energy beam having a wavelength which is not visible to the human eye to a different wavelength which is within the visible range. This wavelength conversion is frequently accomplished with the use of a fluorescent screen which has incident upon it the non-visible energy beam and re-radiates this energy beam as visible light. Such screens are most commonly used in x-ray systems.
In certain applications of a UV laser, the cross-sectional shape of the laser beam and the light intensity variations across the beam are very significant. One such application is in the field of photolithography when forming integrated circuits on a semiconductor wafer. It is desirable to detect the UV laser beam characteristics for laser diagnostic purposes. The resolution required for detecting these beam characteristics is on the order of tens of microns.